TOPIC: Wiring in Parallel

So part way through his NBv3 wiring tutorial, Shameem wires up the three up LED, I think in parallel, but he only bridges the positive pads of the LEDs; the negative ones each got their own wire. I thought wiring in parallel meant bridging both the positives and negatives? Here's the video, beginning at the relevant segment:

It *can* be done by bridging connections, but it's not really needed. Parallel, as far as LEDs go, just means each connection goes:

Battery > (optional switch) > LED > (optional switch) > Back to battery

With the Soundboard acting as a really fancy switch.

If you're running multiple LEDs, everything will wind up bridging somewhere, so it doesn't matter if it's at the battery, on the star, or inside the soundboard's complicated circuitry.

---

Is that alright, or should we go into a big discussion on parallel and series wiring?

He doesn't because the two amber dies need resistors but not the white one. Plus I've been told it's a better practice to resistor each die individually.

You can wire in parallel without bridging the pads. You wire each pad separately and then join the corresponding wires together.

If you'd like another NB install video, Madcow did an updated one for the v3. In it he wires a tri-LED in parallel without bridging any pads.



EDIT: beaten by Kouri's better explanation.

I honestly wouldn't mind. I've had a lot of fun learning about the stuff so far, but I don't know what questions to ask until I hit a snag XD Originally I thought I needed to have my two RB LEDs in series, but someone explained the implications of that so I knew a 3.7v 18650 wouldn't do well for that. So I looked into parallel.

My LED setup is basically the same as the one in the vid, 2 main color LEDs and one for FoC. I mean, if there are particular benefits from bridging everything on the star vs connecting the negatives or positives separately, that'd be interesting to know.

Near as I can tell, series wiring it something to do if you're planning to use a larger voltage battery, like a 7.4v, since it basically combines the forward voltage of the LEDs in the series into one value. More or less?

Simplified version - In Parallel, you add LED Current. In Series, you add LED Voltage. On top of that, if you need LEDs individually addressable, Parallel is the only way, since Series LEDs are tied together to act as one . Use whatever's appropriate for your setup.

Using my Crossguard as an example, I had five 2.7v LEDs to run. Three at 700ma+ each and two at ~500mA each. at roughly 800mA each.

In parallel, I'd need a >2.7v battery that could pump out 4-5A - which a single 18650 can easily do with some small resistors.

In series, the main star would be acting as an 8.1v 700mA+ LED with the combined crossguards as a 5.4v LED at about 500mA. So I'd need a >8.1v battery that could support 1.5-2A, which brings me to a 3x 14500 pack and some beefy resistors.

Parallel is the obvious choice there.

On the flip side, Graflex needed a BrBW star and used a soundboard that needed 5v+ for full-volume audio.

If I wanted to accept the volume loss, I could've settled for an 18650 and wired all the LEDs in parallel with tiny resistors. But I didn't want to lose power.

Parallel wasn't even an option for the 2x 14500 pack I was using. All three LEDs together would've pulled ~3A, and 14500s can only put out ~2A.

Solution was to get the main blade LEDs in series, or replace the battery pack.

So the two blues were wired in series to make a ~7v 1000mA LED with white running parallel at about 3.1v and 1000mA. Blues used a tiny resistor, white needed a beefy one, but the star only pulled about 2A during Flash.

---

As for bridging everything on the star, I used to do it with LED-Supply tri-stars, since the center holes on the star and heatsink could only fit 4 wires max, but it was a real pain having to criss-cross wires. Now I just drill those center holes out to 3/16" to fit all six 26ga wire. Makes things a lot easier on me.

On SF, SH, and TCSS heatsinks, it's a non-issue, since you can use the holes on the perimeter of the star and heatsink.

SF stars are already designed with a bridged positive, and negatives are easy to bridge and often come that way.